I'm building a new machine with the following specs:
Asus p4p800
2.8c cpu
200 gig hd
512mb ddr pc3200
Radeon 9800 pro
Analog 17" monitor
I installed everything and the PC will power up but no video. The
fans will run and power seems to be going, but nothing comes on the
monitor. I put the new video card in my old machine and the card
seems to work fine, ruling that out. That pc will boot up and show me
on the same monitor. On the new machine I have the 4 pin plugged in
and the 20 pin plugged in, but am I missing something? Or did I get
some defective hardware or mess it up myself?
Thanks for any input.
Adam
For a power supply, the +12V should be rated for 12A to 15A, to
work well with the board and video card you've got. The 15A rating
gives you a little breathing room. Check the label on the power
supply for details.
Depending on the exact motherboard model number, the board may
have a Voice POST feature. If it does, connecting an amplified speaker
to the lime colored, Lineout connector on the back of the computer,
as that could give you a voice message as to what is wrong. Voice
POST tends to be a feature of "Deluxe" boards.
Otherwise, you can listen for BIOS beep codes, to try to figure out
what is wrong. Older versions of the BIOS would beep once for every
USB device, while recent versions of the BIOS had beeping disabled -
I hope in an error situation, the board can still beep an error
code for you.
I like the suggestion of trying the "clear the CMOS" procedure.
The only warning about that I would give, is to make sure the
computer is unplugged, before following the procedure listed in
the manual. You don't want any +5VSB on the motherboard, while
using the CLRTC jumper.
If you run out of things to try, do the "cardboard test". I
do this anyway, even if there isn't trouble. Place the new
motherboard on your tabletop, with a piece of cardboard underneath
it. This prevents shorting to any conductor underneath the
motherboard. Plug your components in and experiment with the
motherboard outside the case. It is a lot easier to see what
is going on this way. The PSU can be removed from the case via
four screws in the back of the case. Some motherboard installs
are upset, by the use of an extra standoff touching a copper
conductor on the bottom of the board. Standoffs should only be
placed where they line up with plated holes in the motherboard.
Very little is needed to see a response from the motherboard.
CPU, memory, video card, motherboard, PSU, and something to
momentarily short together the power switch pins on the PANEL
header, should be enough. You can add disk cabling, once you
see the BIOS screen show up.
Make sure the 4 pin and 20 pin are firmly plugged into the board.
Your symptoms almost suggest the 4 pin isn't installed. The fans
can run, because the single +12V wire on the 20 pin connector is
used to power the fans via motherboard headers. But the 4 pin
connector is the exclusive source of power for the CPU. Without
it, the CPU cannot run.
When pressing and plugging stuff into the motherboard, make sure
it is supported underneath at all times, so the board is not
flexed excessively by the insertion force. That requirement
is a little tougher to meet while doing the "cardboard test".
Flexing of the board is not good for large BGA devices, like
the Northbridge and Southbridge, as it can break the solder
joints.
HTH,
Paul
